Audible piston position indicator



Dec' 25, 1951 Ffa. l.

31T ////vW////%\\\\ Patented Dec. 25, 1951 AUDIBLE PISTON POSITION INDICATOR James Vincent Spadola, New York, N. Y., assigner of one-half to Frank Leccese, New York, N. Y.

Application December 17, 1948, Serial No. 65,831 2 anims. (ci. 11s-ci) The present invention relates to piston position indicators such as are used on and in connection with cylinder blocks of internal combustion engines and which serve to effectively reveal the exact top dead-center of the piston, during the compression stroke, whereby to assist a mechanic in timing both ignition and valves, it being the object of the instant invention to better and more satisfactorily attain the Wanted ends `through the adoption and use of an indicator which relies on the functioning of an audible tell-tale signal.

It is a matter of common knowledge that many and varied styles and types of piston locators and position indicators have been devised and offered for use by others than myself. The devices for this purpose,'generally proposed and used, employ a suitable signaling body which is provided with a coupling or an equivalent unit to be screwed into the usual spark plug opening in a cylinder block. Pressure derived from the compression stroke of the reciprocating piston is delivered into the signaling body and acts on the signal so that it is projected or otherwise operated to denote the position of the piston particularly as it reaches top dead-center position. My chief aim is to provide an indicator which is structurally and otherwise diierent from indicators of the forms known to me and, in so doing, to provide one which utilizes a vibratory reed which produces a denite and predetermined tone or sound constituting the desired audible signal and usable as a guide to assist the attending mechanic to set forth to take` care of timing the ignition and valves.

I am aware that in similarly constructed and functioning prior art indicators, some depend on the use of a graduated rod cooperable with an index to enable one to determine, by eye, the piston position. There are others which utilize a visible signal such as an illuminable lamp bulb. In fact, I have ascertained that in a patent to Warburton No..2,413,126, December 24, 1946, which shows a timing checking device, audible reed or sound producing means is employed for signaling purposes. In carrying out the principles of the present invention I improve upon the various prior art devices alluded to and particularly upon the Warburton patent in that I provide a simple assemblage of main parts and a readily insertable and removable reed and reed holder, whereby to provide a simple, efficient yand practical piston position denoting device which is individual, structurally speaking, and otherwise more aptly suited to attain the ends wanted.

A still further objective is to provide a structural assemblage providing an unusually simple,

characterized by four distinct but simple parts;'

namely, a reducer-type coupling or adapter, an axially bored cylinder carried by the coupling, a vibratory pressure responsive reed and a reed holder carrying the reed and removably mounted in the bore of the cylinder.

Other objects and advantages will become more readily apparent from the following description and the accompanying illustrative drawings.

In the drawings, wherein like numerals are employed to designate like parts throughout the views:

Figure l is an elevational view of a piston position indicator constructed in accordance withA the present invention and showing the manner in which the same is, in use, employed.

Figure 2 is an enlarged sectional view taken through the indicator per se.

Figure 3 is a cross-section on the line 3-3 of Figure 2.

Figure 4 is a perspective view of the reed and holder therefor.

Referring now to the drawings by distinguishe ing reference numerals, the cylinder block, which is of any conventional type, is denoted by thef numeral 6 and the spark plug opening (spark plug not shown) is denoted by the numeral 1. After the spark plug is removed from the opening the improved'indicator, my invention, is substituted therefor, and employed until the timing accomplishments have been duly perfected.

The indicator, which is a simple attachment for the cylinder block, is characterized by an ladapter 8, cylindrical body or cylinder 9 carried by the adapter and insertable and removable reed holder I0.

The unit or adapter 8 is a reducer-type coupling and the main cup portion II is internally screw-threaded to accommodate co-acting external threads I2 on the lower end of the body 9 best shown in Figure 2. The screw-threaded reduced attaching neck or nipple is denoted at I3 and this is screwed into the aforementioned spark plug hole 1. The bore through the cylinder or body is axial and the main elongated bore is denoted at I4 and serves to report the sound signal produced by the vibratory pressure responsive reed means. The latter is mounted in the enlarged or counterbored portion I4 which may be conveniently identiiied as the reed chamber.

The means I (I is insertable and held by friction in the stated chamber I5 and is of the construction shown in Figure 4. It comprises a centrally disposable partition I6 having semi-circular lateral assembling and retaining heads I'I and I8 at opposite ends. These heads, which are precision made extend in directions opposite to each other and are thus securely lodged-and held, by friction, in the chamber I5. An air slot is denoted at I9 and this permits passage of the pressured charge developed by the usual piston (not shown). The pressure-responsive vibratory reed is denoted by the numeral 20 and is of T-shaped form and the head portion 2I at one end is riveted or otherwise held on the holding frame. With more specic reference to the holder I an reed it will beV noted that the slot I9 in the plate is of a length greater than the length of the vibratory tang forming the reed proper, that is the tang 29. By reason of this arrangement, the terminal of the tang or reed'is spaced from the adjacent end of the slot I9. This provides a space between the tip of the reed and the adjacent end of Vthe slot to accommodate an instrument (not shown) which may be inserted through the passage in the nipple or neck I3 to assist in either applying or removing said reed holder.

The holder I0 with reed attached is slipped into and held frictionallyor otherwise in the pocket- Y like chamber I5 as broughtout in Figure 2. The

entire device, when assembled in Figure 2 is then applied to the cylinder block 6 by attaching the neck I3 to the spark plug opening l. By placing the gear shift lever in rst and turning the motor by a self-starter (with the key switch 01T) the piston in the cylinder sets the reed into sound producing motion and when the sound stops this indicates that the piston has then reached top dead-center of the compression stroke. Then, the mechanic, fully apprised of the position of the piston, may set forth to take care of timing work, generally the ignition timing. I would explain that the same result can be accomplished by pulling the fan belt by hand toward the operator thereby giving increased tension on the fan belt and by holding the tension on the belt and by turning the fan blade by hand toward the operator, the motor is turneduntil the sound'signal, produced by the stated reed, warns the attendant that top dead-center has been reached.

It is to be noted that the cross-section of the passage or borethrough the nipple i3 is greater than the corresponding cross-section of the chamber I5. This, therefore, provides a passage which is adequate in dimensions for freedom of access to said chamber I5 and the reed holder therein. In fact, it is possible to insert a proper instrument or tool (not shownl and-to dislodge and remove the reed holder from the chamber. By the same token, the reed holderl may be put back into position by way of this enlarged passageway. It is, therefore, unnecessary to disconnect the cylinder 9 from the adapter coupling 8 It is thought that persons skilled in the art to which the invention relates will be able to obtain a clear understanding of the invention after considering the description in connection with the drawings. Therefore, a more lengthy description is regarded as unnecessary.

Minor changes in the shape, size and arrangement of details coming within the field of inventionclaimed may be resorted to in actual practice, if desired.

Having described the invention. what is claimed as new is:

l. A piston position indicator which depends Wholly on sound to Ygive a desired audible signal and which is adapted to be connected to an engine cylinder block by Way of the usual spark plug holes in said block, comprising a solid cylinder having aconstantly' vopen unobstructed axial bore opening through opposite ends of said cylinder,

`the inward end of said bore being axially counterlbored and defining a cylindrical reed chamber,

the latter being cylindrlcai in cross-section a reed holder' embodying a lat rectangular plate of a Y length corresponding to the length of said chamwhen it becomes necessary to replace either the `may check and,v adjust valve tappets accurately.

ber, said plate having a central air slot and having right angularly directedsemi-circular heads atY opposite ends lodge in opposite end portion of said i chamber frictionaliy anchoring said plate in said chamber and partly closing in the outer end p0rtion of said chamber, a pressure-responsiveV reed mounted on said plate in communicative alignment with said slot, said cylinder, at the end adjacent said chamber being externally screw.-

Athreaded, an adapter coupling, said coupling being rigid and internally screw-threaded and screwed on the screw threads provided on said cylinder, said'couping also having a reduced externally screw-threadedl neck and said neck being adapted to Ybe screwed into one of the spark plug holes in a conventional cylinder block, the bore of said neck being of a diameter slightly greater than the-diameter of said chamber to permit the reed holder to be either inserted or re'- moved'by way of said last named bore.

2. The structure specified in claim 1 wherein said slot is of a'length greater than theY length of the coacting portion of the reed whereby the end portion of the slot beyond the corresponding end of the reed may be utilized to accommodate an instrumentality which may be employed indislodging the holder and removing same from the chamber by way of the bore in said'neck. f

, JAMES VINCENT SPADOLA.

REFERENCES CITED The following'references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 751,153 Eisenstein Feb. 2, 1904 870,207 Weiss Nov. 5, 1907 945,371 Bretonneau Jan. 4, 1910 999,567 Kallstrom Aug. 1,V 1911 l' 1,595,945 Kaplon Aug. l0, 1926 1,789,593 Murphy Jan. 20, 1931 Warburton Dec. 24, 1,946 

